Question

using System;
using System.Data.OleDb;
using System.Diagnostics;
using System.IO;

namespace PullData
{
    class Program
    {
        static void Main(string[] args)
        {
            OleDbConnection connLocal = new OleDbConnection("Provider=SAOLEDB.10;Data Source=demo;Persist Security Info=True;User ID=dba;PWD=sql;Location=1.2.3.4");
            OleDbCommand cmdLocal = new OleDbCommand("SELECT tran_num, provider_id, amount, tran_date, collections_go_to, impacts, type, 'TestClinic' AS Clinic FROM transactions WHERE tran_date > '2015-09-27'", connLocal);
            StreamWriter sqlWriter = new StreamWriter(@"C:\Users\Administrator\Desktop\Clinic.txt");


            try
            {
                connLocal.Open();
            }
            catch (Exception connerr) { Debug.WriteLine(connerr.Message); }

            OleDbDataReader readLocal = cmdLocal.ExecuteReader();

            while (readLocal.Read())
            {
                sqlWriter.WriteLine("{0}|{1}|{2}|{3}|{4}|{5}|{6}|{7}", readLocal.GetValue(0).ToString(), readLocal.GetValue(1).ToString(), readLocal.GetValue(2).ToString(), readLocal.GetValue(3).ToString(), readLocal.GetValue(4).ToString(), readLocal.GetValue(5).ToString(), readLocal.GetValue(6).ToString(), readLocal.GetValue(7).ToString());
            }
            readLocal.Close();
            connLocal.Close();
        }
    }
}

嘿所有，

以上是我目前正在测试将查询结果写入txt文件的代码。除了每次尝试运行它之外，所有似乎都有效，它似乎在结束程序之前停止在随机点写入。运行的查询有3370行，以tran_num 227239结尾但是我的txt文件的末尾在到达之前结束并且在这样的行中间被截断：

227233|999|-5.00|11/3/2015 12:00:00 AM|999|C|A|TestClinic
227234|AK|0.00|11/3/2015 12:00:0

我试图用同样的问题运行这几次，我已经将查询运行到数据库（使用相同的应用程序）并且可以看到所有行。有关为什么会发生这种情况的任何想法？感谢

Answer 1

如果出现异常，您应该使用using语句确保您的一次性对象也被关闭。此外，要确保在完成写入后将所有内容刷新到磁盘，请调用StreamWriter Flush方法

static void Main(string[] args)
{
    using(OleDbConnection connLocal = new OleDbConnection(...))         
    using(OleDbCommand cmdLocal = new OleDbCommand("SELECT tran_num, provider_id, amount, tran_date, collections_go_to, impacts, type, 'TestClinic' AS Clinic FROM transactions WHERE tran_date > '2015-09-27'", connLocal))
    using(StreamWriter sqlWriter = new StreamWriter(@"C:\Users\Administrator\Desktop\Clinic.txt"))

    {
        try
        {
            connLocal.Open();
            using(OleDbDataReader readLocal = cmdLocal.ExecuteReader())
            {
                 while (readLocal.Read())
                 {
                    sqlWriter.WriteLine("{0}|{1}|{2}|{3}|{4}|{5}|{6}|{7}", 
                    readLocal.GetValue(0).ToString(), 
                    readLocal.GetValue(1).ToString(),
                    readLocal.GetValue(2).ToString(), 
                    readLocal.GetValue(3).ToString(), 
                    readLocal.GetValue(4).ToString(), 
                    readLocal.GetValue(5).ToString(), 
                    readLocal.GetValue(6).ToString(), 
                    readLocal.GetValue(7).ToString());
                }
            }
            sqlWriter.Flush();
       }
       catch (Exception connerr) { Debug.WriteLine(connerr.Message); }
   }
}

另请注意，我已将所有代码包含在try / catch中，而不仅仅是打开连接并删除了对Close的调用，因为当您从using块中退出时会自动调用它。

C＃StreamWriter在完成之前停止？

1 个答案: